1. Field of the Invention
This disclosure relates to an image formation apparatus such as an electrophotographic printer, a copying machine, or a facsimile. The invention particularly relates to a fixing device mounted on the image formation apparatus and configured to fix a toner image formed on a recording medium, and to a method of manufacturing a fixing roller to be mounted on the fixing device.
2. Description of Related Art
A conventional electrophotographic image formation apparatus widely uses a thermal roll type fixing device. The thermal roll type fixing device includes a fixing roller and a pressure roller and is configured to thermally fuse and fix a toner image attached on a recording sheet while transporting the recording sheet between the heated fixing roller and the pressure roller in pressure-contact with each other. The majority of the thermal roll type fixing devices have a halogen lamp or the like as a fixing heater, inside the fixing roller, to heat the fixing roller. The fixing device having the above configuration may employ a method of reducing the thermal capacity of the fixing roller by making a core of the fixing roller thinner in order to shorten the warm-up time to heat the fixing roller from room temperature to a given temperature required for a fixing process (for example, see FIG. 1, paragraph 0021 of Patent Literature 1: Japanese Patent Application Publication No. 2004-361839).